England completed a crushing 347-run victory over Australia with a day to spare in the second Ashes Test on Sunday to take a 2-0 lead in the five-match series.
Set 583 runs to level the series, Australia succumbed for 235 in their second innings with four balls remaining on the fourth day.
England off-spinner Graeme Swann, who was again the pick of the bowlers, secured the victory when he dismissed James Pattinson lbw for 35 after a battling last wicket stand with Ryan Harris (16 not out).
Swann finished with four for 78 to give him match figures of nine for 122.
But Joe Root, who missed the opportunity of becoming only the second Englishman to score a double hundred in an Ashes Test at Lord's when he was caught for 180, dismissed them both in consecutive overs with his occasional off-spin.
Clarke and Khawaja batted throughout most of the afternoon session before Clarke flicked an innocuous Root delivery straight to England captain Alastair Cook at leg-slip.
Khawaja followed in Root's next over when a ball spun sharply away from the left-hander out of the rough, caught the edge of the bat and carried to James Anderson at second slip.
Clarke had earlier survived a peppering from Stuart Broad, who hit him on the chest, shoulder and finally on the helmet.
The Australian captain, who rarely hooks and whose long-standing back injury makes it difficult for him to duck, survived the barrage and used his quick footwork to nullify the threat of Swann at the Nursery end.
Khawaja, one of five left-handers in the Australian lineup, looked controlled and compact, playing Swann from the crease and hooking Broad for two boundaries.
He brought up his second Test fifty with six boundaries by flicking the second ball of Joe Root's first over of off-spin to leg for two. Clarke followed suit with his 27th Test half-century including seven fours before he gifted his wicket.
The Australian tail lingered until almost the close of play, helped by dropped catches from Root and Anderson, before Swann wrapped up the match.
In the morning session, Cook declared his team's second innings closed on 349 for seven after Root had added only two to his overnight score.
The young Yorkshireman tried an ambitious scoop shot over his head off Ryan Harris but the ball looped to Smith at third man.
Jonny Bairstow was the only other batsman to fall in the final 15 minutes of the England innings. After hitting Ashton Agar straight back over his head for six, Bairstow played an indifferent shot outside his off-stump to Harris and was caught behind for 20.
Shane Watson made his customary bright start with 20 from 23 balls with three boundaries when Australia batted again before making his customary early exit.
The burly Australian opener planted his left leg straight down the pitch to Anderson and was given out lbw for the second time in the match. This time, Watson did not waste a referral to the third umpire and instead trudged back grim-faced to the Pavilion.
Cook introduced Swann for the 10th over and the spinner responded by knocking back Chris Rogers' off-stump with his fifth ball.
Rogers (6) had already left two deliveries which had spun extravagantly away from the left-hander out of the bowler's footmarks and was fooled by a flatter, faster delivery which slid straight on.
Swann struck again with a similar delivery which hit another of Australia's left-handers Phillip Hughes (1) on the back pad and Clarke survived a stumping opportunity to wicketkeeper Matt Prior off Swann after scoring two.
Image: Graeme Swann is mobbed by teammates after taking the final wicket of James Pattinson
Photograph: Gareth Copley/Getty Images
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